There are a lot of shops that are doing ppf. Go with one that will be good with communicating what you want and compare prices.
Ones that are starting up will probably do so at a cheaper price to build the clientele. Ones that have been doing it for a while may possibly be more experienced...
If you're locked and you get free oil changes, I say go to whichever dealer is convenient for you. Longo is my personal favorite, but that's convenient for me.
If you're unlocked, I say go to a specialty shop. You have lots of options in your area. Build a relationship with them and trust their...
The MHD platform (along with other tuning platforms) has the option of a GTS roar on start up. I had it on. I was told it's kinda glitchy, so it's recommended to turn it off and is what's causing the issue. I don't know if it fixes it as I don't have a means of getting the issue to happen. But...
I just did the whole process a month ago. Dyno and all and reached about 480whp/570wtq. Last three runs made 480 hp, with a slow increase in torque every time. So we didn't wanna push it any more for the 500hp (close enough) and left it under a comfortable spot (below 600) for the torque.